A hip replacement has been made out of Ti-120 (a Titanium alloy). The designers conducted a simulation of the device, and with each step that a typical patient takes, a stress of 140 MPa develops at the weakest point on the device. A typical patient takes 2500 steps/day. How long will it take for the joint to fail? (Or, if it won’t fail, why not? Hint: see page 117 in the textbook.) What (potentially dangerous) assumptions about the environment have we made that enables us to predict this lifetime?